Installation crashed while writing on the partition

Thank you for taking the time to report this issue and helping to make Ubuntu better. Examining the information you have given us, this does not appear to be a bug report so we are closing it and converting it to a question in the support tracker. We understand the difficulties you are facing, but it is better to raise problems you are having in the support tracker at https://answers.launchpad.net/ubuntu if you are uncertain if they are bugs. You can also find help with your problem in the support forum of your local Ubuntu community http://loco.ubuntu.com/ or asking at https://askubuntu.com or https://ubuntuforums.org. For help on reporting bugs, see https://help.ubuntu.com/community/ReportingBugs.

Erich saw the [bug] report before I did; I'd have switched the bug report to invalid as well; but I'd have used a 'squashfs' reply, part of which (modified) is below

This package failure looks like it was caused by bad ISO download, corrupted install media, or device failure. eg. look in the logs and you'll see messages like those I've provided at the end of my comment.

Please see : https://tutorials.ubuntu.com/tutorial/tutorial-how-to-verify-ubuntu#0
This bug however will be marked a duplicate of https://bugs.launchpad.net/ubuntu/+bug/1874662

Dec 25 21:04:52 ubuntu kernel: [ 1799.384740] SQUASHFS error: zlib decompression failed, data probably corrupt
Dec 25 21:04:52 ubuntu kernel: [ 1799.384749] SQUASHFS error: squashfs_read_data failed to read block 0x245c51b0
Dec 25 21:04:52 ubuntu kernel: [ 1799.387310] SQUASHFS error: zlib decompression failed, data probably corrupt
Dec 25 21:04:52 ubuntu kernel: [ 1799.387317] SQUASHFS error: squashfs_read_data failed to read block 0x245c51b0

Thank you for taking the time to report this issue and helping to make Ubuntu better.

ie.

- either you have a faulty ISO (did you verify it as being perfect? https://tutorials.ubuntu.com/tutorial/tutorial-how-to-verify-ubuntu#0)

- or the write to installation media was flawed? (did you verify that? for bionic or 18.04 see https://help.ubuntu.com/community/Installation/CDIntegrityCheck)

The squashfs errors are because the installer was unable to read valid data from the installation media (usually thumb-drive) meaning either ISO or write to media was flawed; the checks in prior steps should have alerted you to that.

In my experience its most commonly the write to your installation media (did you use appropriate software for the bionic/18.04 system? and thumb-drive media is made to cost so errors just happen, about 5-8% of failures can be expected on Sandisk media, but more on cheaper media as the ISO is a largish file; try a different thumb-drive as no validation exists on that consumer media).